Mechanical pencil with screw feed



Aug. 1., 1950 F. M. AIMES MECHANICAL PENCIL WITH SCREW FEED med-Feb. 10,1950 l H 1 I. H I 1 l I I Q 1 i ,i i a :1

INVENTOR ATTORNEY Patented Aug. 1, 1950 UNITED STATES PATENT OFFICE fMECHANICAL PENCIL WITH SCREW FEED Francis M. Aimee, Maiden Bridge, N. Y.

Application February 10, 1950, Serial No. 143,431

This invention relates to what are generally referred to as mechanicalpencils. More particularly, the invention deals with devices of thistype and kind having a simple and economical screw mechanism for thepositive feeding of a lead in forward and reverse directions, wherebythe device can be produced and sold at a very nominal cost and, at thesame time, a strong, durable and long-lasting device is provided.

The novel features of the invention will be best understood from thefollowing descriptions, when taken together with the accompanyingdrawing, in which certain embodiments of the invention are disclosedand, in which, the separate parts are designated by suitable referencecharacters in each of the views and, in which:

Fig. 1 is a side and sectional View of a pencil made according to myinvention diagrammatically illustrating a lead in extended position foruse.

Fig. 2 is an enlarged section on the line 2--2 of Fig. 1. i

Fig. 3 is a view similar to Fig. 1 showing another form of construction;and

Fig. 4 is an enlarged section on the line 4-4 of Fig. 3.

In Fig. 1 of the drawing, I have shown a pencil 6 Claims. (Cl. 120-18)comprising a contracted and more or less bulletshaped tip end Ill, anelongated tubular barrel I l and a feed plunger [2. The barrel H has aninwardly spun or fashioned flange end I3 engaging the groove I4 in thetip ill.

The feed plunger 12 has a spiral feed groove l5 engaged by two or moreinwardly-pressed keybeads It On the barrel ii to control feed of theplunger 12 by rotation of the barrel with respect to the tip.

Extending from what might be termed the lower end of the barrel,centrally thereof, is a rectangular rod ll which fits in a correspondingrectangular portion [8 of the bore 19 of the tip ll]. At the end of therod 18 is a spring clip portion 20 for engaging a lead 2| to providefrictional or positive feeding of the lead in the tip ill; the bore 19of the tip H) has a reduced guide bore 22 at its contracted end forsupport and slight frictional engagement with the lead 2|, this end ofthe section being split in accordance with the sectional view of Fig. 4,the latter being specifically applied to Fig. 3, but the tip portion ofboth forms of pencils shown is, in this respect, the same.

Considering now Fig. 3 of the drawing, here is shown a tip NJ, generallysimilar to the tip l0, and at l l is shown a barrel, the barrel beingcoupled with the tip Ill through an intermediate sleeve 23 having akey-engagement with the tip H) as at 24 for free rotation thereon.

The inner end of the sleeve 23, beyond the limits of the tip ID, has anenlarged internally threaded nut portion 25, upon which the barrel l Ihas a pressed or other firm mounting, so that the sleeve 23 and barrelII will operate as one unit. The bore IQ of the tip Ill is also ofrectangular cross-sectional form to key itself with a rectangular rod 26which differs from the rod l l primarily in being of larger diameter andhaving corner portions of the rods fashioned to form thread sections 2'!for operative engagement with the threads of the nut 25, so as to feedthe bar 26 longitudinally of the tip In in expelling and repelling thelead which is mounted on the clip 28, similar to the clip 20'. The leadis not shown in Fi .3. i

The tip III has a small bore end 22', similar to the bore 22 and, asseen at 29 in Fig. 4. of the drawing, the contracted end of the tip issplit so as to provide slight spring properties to this end forsupporting engagement with the lead and to compensate for slightvariances in diameters of the lead. 1

In both forms of the construction shown, the lead is positively extendedor retracted by rota.- tion of the tip and barrel or the sleeve 23 as inFig. 1, one with respect to the other.

From a standpoint of description, the complete mechanical pencil can besaid to comprise a tip end and a barrel end with a plunger movedpositively in both directions axially of the tip and, barrel in the feedof a lead supported thereon. In this connection, the rod 26 of Fig. 3 isthe plunger, as is also the rod end ll of the plunger l 2. In Fig. 1,the enlarged portion of the plunger has a screw thread or screw feedengagement directly with the barrel, whereas in Fig. 3, this engagementis with the nut portion of the sleeve which is fixed to the barrel.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent is:

l. A mechanical pencil of the character described, comprising a barrelpart and a tip end rotatably coupled with the barrel, 2. plunger mountedin and movable longitudinally of said barrel and tip, said tip having arectangular bore, the plunger having a rectangular portion engaging therectangular bore in the tip to key the tip and rectangular portion ofthe plunger against relative rotation, means for frictionally supportinga lead on the rectangular portion of said plunger, the tip having acontracted reduced bore-end through which a lead is adapted to pass, andcooperating means on the barrel and plunger providing longitudinalmovement of the plunger axially of said tip upon relative rotation ofthe barrel and the tip.

2. A mechanical pencil of the character described, comprising a barrelpart and a tip end. rotatably coupled with, the barrel, a plungermounted inand movable longitudinally of said barrel and tip, said tiphaving a rectangular bore, the plunger having a rectangular portionengaging the rectangular bore in the tip to key the tip and rectangularportion of the plunger against relative rotation, means for frictionallysupporting a lead on the rectangular portion of said plunger, the tiphaving a contracted reduced bore-end through which a lead is adapted topass, cooperating means plunger providing longitudinal movement of theplunger axially of said. tip upon relative rotation of the barrel andtip, and said last, named means comprising a spiral groove on theplunger and an indentation on the barrel operatively engaging saidgroove.

3., A mechanical pencil of the character described, comprising a barrelpart and a tip end rotatably coupled. with the barrel, plunger mountedin and movable longitudinally of said barrel and tip, said, tip having arectangular bore, the plunger having a rectangular portion engaging therectangular bore in the tip to key the tip and rectangular portion ofthe plunger against relative rotation, means for frictionally supportinga lead on. the rectangular portion of said plunger, the tip having acontracted reduced bore-end through which av lead. is adapted to pass,coop crating means on the barrel and plunger provid ing longitudinalmovement of the plunger axially of said. tip upon relative rotation ofthe barrel and tip, said last named means comprising a nut portion onthe barrel, and thread sections on said plunger operatively en agingsaid nut portion..

a. A mechanical pencil of the character described, comprising a barrelpart and a tip end rotatably coupled With the barrel, a plunger mountedin and movable longitudinally of said barrel and tip, said tip having a,rectangular bore, the plunger having a rectangular portion engagon thebarrel and ing the rectangular bore in the tip to key the tip andrectangular portion of the plunger against relative rotation, means forfrictionally supporting a lead on the rectangular portion of saidplunger, the tip having a contracted reduced bore-end through which alead is adapted to pass, cooperating means on the barrel and plungerproviding longitudinal movement of the plunger axially of said tip uponrelative rotation of the barrel and tip, said last named meanscomprising a nut portion on the barrel, thread sections on said plungeroperatively engaging said nut portion, and said nut portion constitutingpart of a sleeve interposed between the barrel and said tip.

5. A mechanical pencil of the character described, comprising a barrelpart and a tip end rotatably' coupled with the barrel, a plunger mountedin and movable longitudinally of said barrel and tip, said tip having arectangular bore, the plunger having a rectangular portion engaging therectangular bore in the tip to key the tip and rectangular portion ofthe plunger against relative rotation, means for frictionally supportinga lead on the rectangular portion of said plunger, the tip having acontracted reduced bore-end through which a lead is adapted to pass,cooperating means on the barrel and plunger providing longitudinalmovement of the plunger axially of said tip upon relative rotation ofthe barrel and tip, and said contracted bore end of the tip being split.

6. A mechanical pencil of the character described, comprising a barrelpart and a tip part having a contracted end, the tip part hav ing arectangular bore extending longitudinally throughout the major portionof the length thereof, said bore terminating at the contracted end ofthe tip in a small diameter lead guide bore, a plunger movablelongitudinally of the barrel part, said plunger having a rectangularportion conforming with and fitting snugly in the bore of said tip toprevent relative rotary movement one with respect to the other, andcooperating means between the plunger and barrel for feeding the plungerlongitudinally of the tip upon relative rotation of the tip and barrel.

FRANCIS M. AIMES.

No references cited.

